A research team has shown the viability of producing electrode materials for lithium-ion batteries using affordable components (LIBs). This approach might lessen the industrial dependency on rare metals like cobalt and nickel if it were investigated further.
On April 11, 2022, specifics of their findings were released in the American Chemical Society journal ACS Applied Energy Materials.
Because they create a suitable crystal structure for the essential cathode materials of LIBs, rare metals are frequently employed. Lithium is readily and irreversibly removed from or injected into these materials.
For a very long time, scientists have been trying to find economical techniques to add additional elements to crystal structures. However, the solubility of other elements is constrained, just as only a specific quantity of salt may dissolve in water.
The research team at Tohoku University’s Institute for Materials Research (IMR), under the direction of professor Tetsu Ichitsubo, adopted a different approach.
Utilizing the energy gain from the state of randomness known as “configurational entropy” in a material, they increased the solubility of the component elements and created novel composition electrode materials: LiCr1/4Mn1/4Co1/4Ni1/4O2 and LiCr1/5Mn1/5Fe1/5Co1/5Ni1/5O2. This significantly reduced the use of cobalt and nickel.
Increasing configurational entropy also theoretically raises the stabilization of the electrode material, contributing to the safety of the whole battery.
Tomoya Kawaguchi
“Our approach unlocks the potential of other unused elements and will enable us to optimize multiple electrode properties simultaneously thanks to flexible material designs,” says Ichitsubo.
The materials synthesized by the new method may also improve the safety of LIBs. Tomoya Kawaguchi, assistant professor at IMR and corresponding author of the paper states, “Increasing configurational entropy also theoretically raises the stabilization of the electrode material, contributing to the safety of the whole battery.”
With the use of these new materials, Ichitsubo and his team further clarified the mechanisms of degradation impacting the battery cycle. The high-entropy strategy will be used as a roadmap for creating new, high-performance materials.
The ability to synthesis new electrode materials offers up new directions for research into LIBs, even though the cyclability and capacity did not match those of traditional LIBs at the time.
